托福口语 Task 4

Today we're going to talk about a fascinating concept in animal behavior called 'sensory exploitation.' This is when a species evolves a trait that takes advantage of a pre-existing sensory bias in another species, often to enhance its own reproductive success. Let me give you two clear examples. First, consider the male túngara frog. Females have an innate preference for low-frequency 'chuck' sounds because those sounds are similar to the calls of larger, more dominant frogs, which are better at defending territory. Males have evolved to add these extra chucks to their calls, even though it makes them more vulnerable to predators. This exploits the females' existing bias toward low-frequency sounds. Second, look at the male guppy. Female guppies naturally prefer orange-colored objects because orange resembles ripe fruit, which is a food source in their environment. Over time, male guppies have developed bright orange spots on their bodies. These spots aren't just attractive—they trick the females' food-related visual bias, making the males seem more appealing as mates. So in both cases, the males have evolved traits that exploit pre-existing sensory preferences in females.